include/linux/netlink.h

   1 #ifndef __LINUX_NETLINK_H
   2 #define __LINUX_NETLINK_H
   3
   4
   5 #include <linux/capability.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/export.h>
   8 #include <net/scm.h>
   9 #include <uapi/linux/netlink.h>
  10
  11 struct net;
  12
  13 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
  14 {
  15         return (struct nlmsghdr *)skb->data;
  16 }
  17
  18 struct netlink_skb_parms {
  19         struct scm_creds        creds;          /* Skb credentials      */
  20         __u32                   portid;
  21         __u32                   dst_group;
  22         struct sock             *ssk;
  23 };
  24
  25 #define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
  26 #define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
  27
  28
  29 extern void netlink_table_grab(void);
  30 extern void netlink_table_ungrab(void);
  31
  32 #define NL_CFG_F_NONROOT_RECV   (1 << 0)
  33 #define NL_CFG_F_NONROOT_SEND   (1 << 1)
  34
  35 /* optional Netlink kernel configuration parameters */
  36 struct netlink_kernel_cfg {
  37         unsigned int    groups;
  38         unsigned int    flags;
  39         void            (*input)(struct sk_buff *skb);
  40         struct mutex    *cb_mutex;
  41         void            (*bind)(int group);
  42 };
  43
  44 extern struct sock *__netlink_kernel_create(struct net *net, int unit,
  45                                             struct module *module,
  46                                             struct netlink_kernel_cfg *cfg);
  47 static inline struct sock *
  48 netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
  49 {
  50         return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
  51 }
  52
  53 extern void netlink_kernel_release(struct sock *sk);
  54 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
  55 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
  56 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  57 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
  58 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
  59 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
  60 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
  61 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
  62                              __u32 group, gfp_t allocation);
  63 extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  64         __u32 portid, __u32 group, gfp_t allocation,
  65         int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  66         void *filter_data);
  67 extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
  68 extern int netlink_register_notifier(struct notifier_block *nb);
  69 extern int netlink_unregister_notifier(struct notifier_block *nb);
  70
  71 /* finegrained unicast helpers: */
  72 struct sock *netlink_getsockbyfilp(struct file *filp);
  73 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
  74                       long *timeo, struct sock *ssk);
  75 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
  76 int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
  77
  78 /*
  79  *      skb should fit one page. This choice is good for headerless malloc.
  80  *      But we should limit to 8K so that userspace does not have to
  81  *      use enormous buffer sizes on recvmsg() calls just to avoid
  82  *      MSG_TRUNC when PAGE_SIZE is very large.
  83  */
  84 #if PAGE_SIZE < 8192UL
  85 #define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
  86 #else
  87 #define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
  88 #endif
  89
  90 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
  91
  92
  93 struct netlink_callback {
  94         struct sk_buff          *skb;
  95         const struct nlmsghdr   *nlh;
  96         int                     (*dump)(struct sk_buff * skb,
  97                                         struct netlink_callback *cb);
  98         int                     (*done)(struct netlink_callback *cb);
  99         void                    *data;
 100         /* the module that dump function belong to */
 101         struct module           *module;
 102         u16                     family;
 103         u16                     min_dump_alloc;
 104         unsigned int            prev_seq, seq;
 105         long                    args[6];
 106 };
 107
 108 struct netlink_notify {
 109         struct net *net;
 110         int portid;
 111         int protocol;
 112 };
 113
 114 struct nlmsghdr *
 115 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
 116
 117 struct netlink_dump_control {
 118         int (*dump)(struct sk_buff *skb, struct netlink_callback *);
 119         int (*done)(struct netlink_callback *);
 120         void *data;
 121         struct module *module;
 122         u16 min_dump_alloc;
 123 };
 124
 125 extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 126                                 const struct nlmsghdr *nlh,
 127                                 struct netlink_dump_control *control);
 128 static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 129                                      const struct nlmsghdr *nlh,
 130                                      struct netlink_dump_control *control)
 131 {
 132         if (!control->module)
 133                 control->module = THIS_MODULE;
 134
 135         return __netlink_dump_start(ssk, skb, nlh, control);
 136 }
 137
 138 #endif  /* __LINUX_NETLINK_H */